1. Field of the Invention
The present invention relates to a heat conductive silicone composition which, even upon high-level packing with a heat conductive filler in order to achieve a silicone composition that is highly heat conductive, still exhibits favorable handling and moldability properties, and also exhibits favorable physical properties following curing.
2. Description of the Prior Art
As printed circuit boards and hybrid ICs with mounted electronic components such as transistors, ICs, and memory modules and the like have trended towards higher levels of packaging density and higher levels of integration, heat conductive silicone compositions such as heat conductive silicone greases, heat conductive silicone gel compositions, and heat conductive silicone rubber compositions have been increasingly used to ensure effective heat radiation from these devices.
In order to improve the thermal conductivity of these types of heat conductive silicone compositions by high-level packing of the composition with a heat conductive filler, heat conductive silicone rubber compositions comprising an organopolysiloxane, a hydrolysable group-containing methylpolysiloxane, a heat conductive filler, and a curing agent (patent reference 1), and heat conductive silicone rubber compositions comprising a curable organopolysiloxane, a curing agent, and a heat conductive filler, wherein the surface of the filler has been treated with an oligosiloxane containing silicon atom-bonded alkoxy groups (patent reference 2) have already been proposed.
However, if an attempt is made to further improve the thermal conductivity of these types of heat conductive silicone compositions by the high-level packing of a heat conductive filler such as alumina or the like, then a problem arises in that the physical properties of the compositions deteriorate significantly following curing.
[Patent Reference 1] U.S. Pat. No. 6,306,957
[Patent Reference 2] U.S. Pat. No. 6,380,301